The invention pertains to microcircuit cards and, more particularly, the object of the invention is microcircuit cards, protected against intrusion. Microcircuit cards are chiefly used as media for the storage of information that is often confidential, notably codes giving access to services. To ensure the requisite security of operation, it is essential for such microcircuit cards to be protected against intrusion by dishonest individuals who seek to violate the confidentiality of the information that these cards may carry. The means of observation that dishonest individuals might use are either static means wherein the card is observed without any active means of intrusion, or dynamic means wherein the card is observed by simulating the conditions of its operation.
A known way of protecting the stored items of information against intrusion by static means lies in "concealing" them to the maximum extent in the microcircuit. By contrast, there is no method, to date, of protection against an intrusion where "dynamic" observation means are used.
An object of the invention is a microcircuit card protected against intrusion by dynamic means.